Support disk bearings for open-end spinning machines as known from German Patent Disclosure DE 40 19 029 have four paired support disk assemblies connected via bearing shafts. In this case, the support disk assemblies are disposed such that their respective circumferential peripheries form a wedge-shaped gap between them, in which the rotary shaft of the spinning rotor is supported while being driven by a tangential belt. This type of bearing is suited for the highest rotary rpm with a satisfactory service life.
The support disk assemblies of such support disk bearings typically comprise a disk-shaped main body preferably of aluminum that has a central axial bore to receive the bearing shaft, and a annular collar disposed at the outer circumference of the peripheral rim of the main body to form a peripheral bearing surface. In most cases, the collar comprises an abrasion-resistant elastomer that is fixedly attached to the rim by means of gluing or vulcanization.
Because of the high rotational speed of the rotary shaft, the annular collar is exposed to a relatively high amount of wear. Although the attainable service life of such support disk bearings is relatively long overall, defects on the annular collar are the most common cause of bearing damage.
With the support disk assemblies used presently, it is hardly possible, or at the least very uneconomical, to refurbish worn support disk assemblies, because, for example, the annular collar is difficult to remove. It has therefore been standard practice up to now to change the entire support disk bearing when the annular collar of a support disk assembly is damaged.
In the past attempts were made to make the operation of an open-end spinning machine more economical through the use of low-priced support disk assemblies; however, the proposed support disk assemblies have certain disadvantages.
For example, a support disk is known from German Patent Disclosure DE 32 05 566 A, wherein a rim is formed from a one-piece, shell-like, sheet metal machined part. A plastic annular collar is injection-molded onto the sheet metal machined part. Support disk assemblies of this type that are produced as sheet metal drawn pieces are more cost-effective to produce than support disk assemblies whose rims are formed by a main body made entirely of aluminum, but the fundamental problem of replacing the entire support disk when the collar is worn could not be solved.
A support disk with an exchangeable annular collar is known from German Patent Disclosure DE 36 30 257 A (U.S. Pat. No. 4,890,942). This known support disk assembly has a disk body formed of two disk members whose respective annular clamping rims serve as clamping portions to secure the annular collar. The disk members can be connected via connecting elements to cause the clamping portions of their respective rims to partially clamp a radially inward extent of the side surfaces of the annular collar that extend convergently in the direction of the collar's peripheral bearing surface. The most significant disadvantage of these support disk assemblies is their inadequate true-running characteristics.
DE 40 19 029 A, identified above, discloses a similar design for a support disk assembly wherein a central main body that forms a peripheral rim and two lateral holding elements secure exchangeable annular collars, but the running collars in this support disk assembly also have the disadvantages known from DE 36 30 257 A.